Commitments and Contingencies (Details) (USD $)	3 Months Ended		6 Months Ended
	Jun. 30, 2014	Jun. 30, 2013	Jun. 30, 2014	Jun. 30, 2013
Commitments and Contingencies [Line Items]
Rental expense for operating leases	$ 2,400,000	$ 2,300,000	$ 4,600,000	$ 4,800,000
Defined benefit plan employer matching contribution on first five percent of employee compensation			50.00%
Defined benefit plan employer contribution limit			6,000
Defined benefit plan employer contribution vesting period			5 years
Maximum [Member]
Commitments and Contingencies [Line Items]
Percentage of employees' eligible compensation for employer matching contribution			5.00%
Salaries And Related Expenses [Member]
Commitments and Contingencies [Line Items]
Defined benefit plan employer contribution	$ 300,000	$ 200,000	$ 600,000	$ 500,000